Teslong is focusing on manufacturing and exporting industrial endoscope with fast shipping and reliable after-sale service

8X25 Haute qualité Hd grand-angle Portable Bas niveau de lumière Nuit Vision mini HD film vert Jumelles télescope monoculaire. MINI Monoculaire Vert Zoom BAK4 Maritime Poche HD Télescope Spyglass Spotting ScopeUSD 13.26-14.35/piece HSEAYM 35X50 Monoculaires Télescope Optique HD Chasse Tourisme Oculaire BAK4 La Vie Imperméable À L'eau Voyage Vision Portée JumellesUSD …

pre-1775 refracting telescopes. e.g. “dollond” advanced search options + Include in full text search: Include in full text search: Maker Manufacturing Location

Here is an 8-inch" mirror that I did "just for fun"; I did this to push my foundry to the limit. However, the pour is too thin. To get to a full 8-inch mirror, I will have to make a new furnace as well as construct new tools. This is the bottom of the pour and was very clean. Even so, sand is picked up in the melt.

Speculum metal is a mixture of around two-thirds copper and one-third tin making a white brittle alloy that can be polished to make a highly reflective surface. It was used historically to make different kinds of mirrors from personal grooming aids to reflecting telescope optical mirrors until it was replaced by more modern materials. Large speculum metal mirrors are hard to manufacture and ...

Jun 08, 2017· 🚀 Acheter un télescope pour pas cher. ... AstronoGeek 571,910 views. 21:18. How to make a telescope out of paper easy origami - Duration: 10:37. How To Make Origami Recommended for ...

Austrian manufacturer of high quality binoculars, spotting scopes, and tripods. Perfect for and nature observations. Visit our online shop!

Specula Sizes: 4.75mm for adults and 2.75mm for children and infants. A protective hard plastic case is also included for storing your otoscope when not in use. Inside the package, you will also find a weblink with 30, high-resolution eardrum photos of healthy and diseased eardrums, as well as an instructional sheet describing how to properly ...

The Original Speculum Telescope Mirror is not only the greatest science nerd gift ever, it is also a real speculum metal telescope mirror blank. It can be easily ground into a working, turn of the century, telescope mirror. ... When the pour is made little surface imperfections can be created (see video). So it's going to take time to grind ...

A telescope is an instrument designed for the observation of remote objects and the collection of electromagnetic radiation. The first known practically functioning telescopes were invented in the Netherlands at the beginning of the 17th century

May 23, 2019· La buée sur un télescope est une des choses qui peu vous faire arrêter une soirée d'observation exactement de la même manière que l'arrivé des nuages. Voici donc une vidéo ou …

Casting a Large, Light-Weight Telescope Mirror From Recycled Glass: The first photo below shows a 12.5 inch diameter, 1.5 inch thick, telescope mirror blank, made from recycled glass, that has been lightened by casting the mirror in a mold that made lots of hexagon-shaped pockets in …

40 1!,nivWs Otrc .Jhttdltt.~tZC,f~r ?~tle,~copes. be found at most of the Philosophical Instrument tttaker,s; a telescopof this kind may appear at first to lie guod, but in a shortsp;tce of time may afford a very ittdistittct view of srtclr objects as are seen throui it, in cottaedttetice of the tarnishing of the metallic reflectors, Different workmen have used diflbrent mixtures, although ...

Les Fabrication telescope sont très populaires aux North America, en Western Europet en Domestic Market. Faites le choix de produits certifiés en vous fournissant auprès de producteurs agréés dont 967 possèdent la certification ISO9001, 296 la certification Other et 77 la certification BSCI.

library-telescope-program. The Library Telescope Program is a great club project, one that brings members together while benefiting their community. Indeed, it is the perfect outreach program! MILLSTREAM ASTRONOMY CLUB AWARDS ANOTHER LIBRARY TELESCOPE 2 019 saw the presentation of a second library lending telescope in Findlay, Ohio.

Sep 29, 2017· Le BioMobilizer fait enfin son apparition, un engin polyvalent adapté aux spécificités du bois énergie. En collaboration avec le FCBA, l'ADEME …

Nov 17, 2012· Page 2 of 3 - Spectroheliscope at Stellafane - posted in Classic Telescopes: In my defense - I built the crappy platform at home, based on a photograph. And it did manage to survive a Vermont winter without getting blown away. That said, we should have moved it. But we would have lost precious time needed to investigate alignment issues.

Maison 12,5 pouces télescope Dobson Comment construire un télescope Dobson de 12,5 pouces tube fermé. J'ai commencé à construire au printemps de 2008, mais le gros du travail a été fait en juillet 2008 avec la première lumière survenus le 25 juillet. Ce Instructable décrivent la planif

Reflectors & refractors. Early reflectors using speculum metal had some of the record-breaking apertures of the day, but not necessarily high performance. Starting in the 1860s metal coated glass ('Silver on glass') reflector telescopes proved more durable, for example the Crossley Reflector, which continued to be used and upgraded even into the 21st century.

MINIATURE GREGORIAN TELESCOPE, English, c. third quarter 18th century. Measuring 7-1/4" (18 cm) overall, complete with turned brass end cap, the instrument has bright speculum metal mirrors, two-element erecting eyepiece system, and external screw focussing to the secondary mirror. Craftsmanship is excellent, and it gives superb images even in ...

In the very earliest days of telescope making the material of choice was Speculum Metal. This was an alloy of Copper, Tin and Arsenic that was hard and nearly white. Ordinary glass is hard and can be polished, but it does not reflect light well; since it is transparent, most of …

A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image.The reflecting telescope was invented in the 17th century, by Isaac Newton, as an alternative to the refracting telescope which, at that time, was a design that suffered from severe chromatic aberration.

Nov 06, 2012· Nouvelle machine Rousseau : Fulgor 876. Cette machine a la particularité d'avoir un double télescope qui offre 8,50m de portée tout en conservant un encombrement d'une machine de 6,50m. Machine ...

R185 est une machine conçue pour le broyage des déchets végétaux de Les cheveux doivent être liés (sur les épaules). Utiliser uniquement des pièces détachées originales. 7 permet, grâce à un trou, la rotation de la protection à 270° pour éviter que le . basse puissance du broyeur et …

Such speculum metal is exceedingly hard and brittle, takes a fine white polish, and when protected from damp has little liability to tarnish. The process of casting and annealing, in the case of the specula of the great Melbourne telescope, was admirably described by Dr Robinson in Phil. Trans., 1869, 159, p. 135. Shaping, polishing and ...

Detail of Telescope Construction. When the glass is polished enough to reflect some light, it should be tested with the knife-edge test. In a dark room, set the speculum against the wall, and a large lamp, L, Fig. 2, twice the focal length away.

SCHOTT a obtenu un contrat pour la production de substrats de miroirs destinés aux miroirs secondaires (M2) et tertiaires (M3) du Télescope géant européen. M2 sera le plus grand miroir convexe jamais produit. Une deuxième cuve de fusion sera mise en service pour répondre à la forte demande en vitrocéramique ZERODUR®

Such speculum metal is exceedingly hard and brittle, takes a fine white polish, and when protected from damp has little liability to tarnish. The process of casting and annealing, in the case of the specula of the great Melbourne telescope, was admirably described by Dr Robinson in Phil. Trans., 1869, vol. clix. p. 135. Shaping, polishing, and ...

3 janv. 2016 - Comment fabriquer un télescope. Grâce à une combinaison de lentilles et de miroirs, les télescopes permettent de faire apparaitre des objets éloignés comme s'ils étaient plus proches. Si vous n'avez pas de télescope ou de jumelles chez vous...

Tel e*scope, n. [Gr. ? viewing afar, farseeing; ? far, far off + ? a watcher, akin to ? to view: cf. F. t[ e]lescope. See {Telegraph}, and { scope}.] An optical instrument used in viewing distant objects, as the heavenly bodies. [1913 Webster]…

Inflections of 'telescope' (v): (⇒ conjugate) telescopes v 3rd person singular telescoping v pres p verb, present participle: -ing verb used descriptively or to form progressive verb--for example, "a singing ," "It is singing." telescoped v past verb, past simple: Past tense--for example, "He saw the man." "She laughed." telescoped v past p verb, past participle: Verb form used ...

By having the eyepiece at one side of the telescope tube, he viewed objects reflected at an angle from the speculum, as shown in Fig. 1. This telescope, when mirrors of the usual short focus are used, has a very serious fault: the object observed is several degrees of the optical axis, and this causes badly distorted images.

le Newton Skywatcher 150/750 est idéal pour le ciel profond avec un rapport f/d de 5. le Newton Celestron 114/900 est polyvalent et idéal à la fois pour le planétaire et le ciel profond, avec un rapport f/d de 7.9. le Maksutov Skywatcher 127/1500 est idéal pour le planétaire avec un rapport f/d de 11.8.

A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation (such as visible light).The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s (the 17th century), using glass lenses. They found use in terrestrial applications and astronomy. Within a few decades, the reflecting telescope was ...

THE USE AND CARE OF REFLECTING TELESCOPES. By W. F. HOYT, Kansas Wesleyan University, Salina. Read before the Academy, at Topeka, December 30, 1904. N the precision of its adjustments, in the wealth of mechanical de-tails, in the number and intrinsic value of its attachments, the modern telescope is the prince among human instruments. There

5 juin 2020 - Découvrez le tableau "Bricolage et DIY" de philippemeslin sur Pinterest. Voir plus d'idées sur le thème Bricolage, Diy, Outils de menuiserie.